Roll out two-thirds of the pastry between two pieces of lightly floured baking paper to 3mm thick. Line a lightly buttered 30x10cm (12x4in) tart pan (with a removable bottom), trim edges, prick all over with a fork and refrigerate for 1 hour. Roll out remaining pastry to 3mm thick, cut into 1cm strips and refrigerate on a tray for 1 hour.
Preheat oven to 180°C/350°F; beat butter, sugar and orange zest until light and fluffy (1-2 minutes). Beat in eggs, one at a time, and liqueur. Scrape the sides of the bowl, then beat in the almond meal. Spread in the pastry case and bake until filling just sets (12-15 minutes). In the meantime, remove the pastry strips from the fridge. Remove tart from oven, stand for 5 minutes, then very carefully spread the marmalade over the almond filling – be gentle so the jam doesn’t sink in the filling. Arrange pastry strips in a lattice pattern over the top and brush lattice with egg wash/heavy cream, bake until pastry is golden (15 minutes) and filling is bubbly. Remove from the oven and cool the tart in the pan over a wire rack. Dust with icing sugar to serve.

* I doubled this recipe, which gave me 800g pastry; I used 300g for this tart and froze the remaining pastry for another use